It's a vague question. An equally vague answer would be to read books like "Lean Startup". Lean may not be your answer but it will open you up to other things.

It's a vague question. An equally vague answer would be to read books like "Lean Startup". Lean may not be your answer but it will open you up to other things. Validate your idea and business model and if you are satisfied by what you found (i.e. backers ready to spend money upfront), go and build it